The referenced application Ser. No. 06/193,254, of Oct. 1, 1980, by the inventor hereof, discloses a circuit of this type having two similarly poled switching transistors which are connected to bridge the terminals of a direct current supply source. If more than one lamp is operated in such a system, each one of the lamp operating circuits has its own series resonance circuit which is formed by respective ballast inductances and a capacitor. The respective lamp operating circuits and the associated series resonance circuits are connected in parallel.
The referenced application discloses a system which is suitable both for single-lamp as well as for multiple-lamp operation which includes a protective circuit so that, in case of malfunction for example upon non-firing or starting of a lamp, the transistor push-pull switch is disconnected, so that damage to the lamps or to the system is prevented.
The referenced application Ser. No. 06/193,254 further describes a control circuit which triggers the oscillator formed by the ballast inductances and the capacitor, and which includes push-pull connected transistors, so that the series resonance circuit will oscillate reliably as soon as power is connected thereto.